Tracer mechanism for duplicating machines



Dec. 7, 1937.

E. K. JOHANSEN TRACER MECHANISM FOR DUPLICATING MACHINES Original Filed Jan. 27, 1937 4 Sheets-Sheet l xi? i 4 Sheets-Sheet 2 E. K. JOHANSEN TRACER MECHANISM FOR 'DUPLICATING MACHINES Original Filed Jan. 27, 1937 Dec. 7, 19 37.

E. K. JOHANSEN TRACER MECHANISM FOR DUPLICATING MACHINES 4 Sheets-Sheet 3 Original Filed Jan 27, 1937 n h m m i ii a wig? Dec. 7, 1937. E. K. JOHANSEN TRACER MECHANISM FOR DUPLICATING MACHINES Original Filed Jan. 27, 1937 4 Sheets-Sheet} Patented Dec. 7, 1937 UNITED {STATES PATENT OFFICE TRACER MECHANISM .FOR DUPLICATING- MACHINES Einar K. Johansen, Chicago, 11]., asslgnor in Clearing, Machine Corporation, Chicago, 11]., a corporation of Illinois Original applicationlanuary 27,1937, Serial No.

Divided and this applicationJune 21,

1937, Serial No. 149.370

11 Claims.

This application is a division of my co-pend- .ing application number 122,602! filed January 27, 1937.

work piece are controlled by a tracer moving over the surface of a model or pattern to produce the contour of th pattern upon the work,

and is particularly adapted for use with metal wo rking machines, such as milling machines, boring machines, 'planers and the like, and may be built within as a component part of the machine or as an attachment.

The present invention is concerned more particularly with the tracer infconnectionwith the valve mechanism which controls the operation of the machine, and which valve mechanism is in turn controlled bythe tracer, and one of the chle'cts oi the invention isto provide an improved tracer mechanism by which the control may be quickly and easily reversed to permit'reproduction of patterns either in duplicate or in reverse as desired, and at, the same time provide 5 a tracer valve which is of practical and relatively simple construction and yet extremely .ac-

. curate, sensitive and reliable in operation.

To the attainment of these ends and the 'accomplishment of other new and useful objects 30 as will appear, the invention consists in the features of novelty in substantially the/construction, combination and arrangement of the parts hereinafter more fully described and claimed I I and shown in the accompanying drawings il- 35 lustrating this invention, and in which Figure 1 is a general elevational view of a hori zontal boring machine equipped with tracer controlled duplicating mechanism"embodying the features of this invention.

Figure2 is a plan view of the machine shown .in Figure 1.

Figure 3 is a sectional view taken on line 3-4, Figure 2, on an enlarged scale, showing the mechanism for drivingly connecting thetool support and the tracer slide.

Figure 4 is a sectional view taken on line 4 -4,

Figure 3, on an enlarged scale, showing details of the micrometer, adjusting mechanism com- 'Figure3. a

Figure 5 is a sectional view taken on line 5-.-5, Figure 4, I v I Figure '61s a longitudinal sectional view, on an 5.5 enlarged scale, of the front portion of the tracer.

5o prising a part of the connecting mechanism of Figure 7 is a longitudinal sectional view of the rear portion of the tracer.

Figure 8 is a detail sectional view, on an enlarged scale of the tracerarm bearing support.

Figure 9 is a sectional view, on an enlarged 5 scale, of a modified form of the tracer valve and valve control mechanism.

Figure 10 is a detail view partly in elevation and partly in section, on an enlarged scale, of

a modified form' of the tracer valve control 10' means.

By way of illustration, thesinvention has been shown and will be described hereinafter as 'incorporated in a horizontal boring machine, but

' it is to be understood that this is not intended 15 i as a limitation of the invention to the particular machine described, it being contemplated that various changes and modifications may be made by those skilled in the art to adapt the inven-- tion to other types of metal working machines. 0 It will also be understood that various changes in the form, construction and arrangement of the parts may bemade without departing from the spirit and scope of the invention as expressed in the claims.

While-a portion of the machine proper and of the mechanism which is controlled by the tracer and valve will be hereinafter described, it is to be understood that the present invention is directed j particularly to the tracer mechanism and the valve control, the description of the machine being incorporated for the purpose of a clear understanding of the present invention.

Referring more particularly to Figure 1 of the drawings, the machine embodies a horizontally disposed bed i provided at one end with longitudinal guides or ways 2 on which the work support 3 travels. work support comprises a saddle I in direct engagement with the ways 2 for movement along the bed i. and is provided with horizontal transverse guides or ways 5 on which the work table. 6 is mounted for movement transversely of the bed.

The work table 6 carries a vertically disposed; angle plate 1 upon which a work piece 8 and a pattern or model 9 are mounted. Rigidly mounted at the other endof the bed I is an upstanding column iii provided with-verticalguides or ways it on which a spindle'headstock l2 travels. The headstock includes a tool support in the form of a horizontal spindle I3 projecting on the side adjacent the work support and carries a cutting tool It for operating on the work 8. The rear end or the spindle is operatively der I6 to which pressure fluid may be introduced selectively to move the spindle toward and from the work.

Suitable power drive means is provided for rotating the tool spindle l3, for feeding the headstock vertically in either direction, and for feeding the work table 6 transversely of the bed in either direction. In addition, a pump (not shown) driven by an electric motor I8 is arranged to supply 'fluid under pressure to the cylinder l6 for feeding the tool spindle toward or from the work.

As shown in Figure 1, the pump together with the motor l8 and a suitable fluid reservoir or sump is enclosed in a separate casing 20 adapted to be mounted at a convenient position adjacent the machine.

Upon the headstock I2 is rigidly mounted a bracket 2| having a horizontally disposed dovetailed slideway 22 (Figures .2 and 3) in which a slide 23 supporting a tracer 24 is mounted for movement parallel to the axis of the spindle l3.

The tracer is of the type having a tracer arm 25 mounted for slight universal movement with reference to a head or casing 26 and having-a tip 21 shaped substantially like the tool l4 and adapted to engage the surface of the pattern 9 as the tool operates on the work piece 8. Since the tracer head 26 is rigidly mounted on the headstock, the tracer tip and tool move together with the headstock and in'fixed relation as to distance apart so that they describe a series of parallel paths relative to the work and pattern in the combined vertical movement of the headstock and the traversing movements of the work table.

With tracers of this type, movements of the tool l4 toward and from the work at right angles to the traversing path are controlled by valve mechanisms interposed in the hydraulic circuit of the cylinder I 6 and adapted to be actuated by the independent movement of the tracer arm 25 incident to thetip 21 encountering either a rise or depression in the surface of the pattern.

Upon such movement of the tool, it is necessary to impart a proportionate movement to the tracer tending to restore the tracer arm to neutral position and maintain the tip 21 in constant, substantially uniform contact with the pattern.

The relative direction of the tracer movement is dependent upon whether the work is to be a duplicate of the model or a reverse copy of the same, in the first instance the tool and tracer moving to exactly the same extent or degree and in the same direction, while in the latter instance the tool and tracer are moved in opposite directions.

To co-ordinate the movements of the tool and tracer, the tracer slide is arranged to be driven directly from the tool spindle l3 by means of a positive geared driving connection interposed between the slide and spindle.

Referring particularly to Figures 2 and 3, the

mentioned. shaft through the medium of a sleeve 33 keyed to the lower shaft and having clutch teeth 34 engaging with complementary teeth on a sle ve 35 on the shaft 32.

medium of a micrometer au usting mechanism 36 by which the angular relation of the shafts may be varied in infinitely small steps as will appear presently. The sleeve 33 is arranged for movement axially to the shaft 28 to engage or disengage the clutch teeth at will, the teeth being disengaged when the machine is to be operated without tracer control. A yieldable detent 31 (Figure 4) holds'the sleeve in clutch engaging relation.

The upper end of the shaft 32 is journaled in a suitable bearing 38 supported in a gear box 39 Ont-he rear end portion of the bracket 2|. Fast on the upper end of the shaft 32 is a bevel gear 40 adapted to mesh with bevel gears 4| and 42 constituting a. reversible clutch mechanism for driving a transverse shaft 43 journaled in antifriction bearings 44 supported in the gear box 39. The gears 4i and 42 are formed integrally with or rigidly secured to a sleeve 45 splined to the shaft 43 for movement axially thereof. A pinion 46 fast on the shaft 43 is arranged to mesh with a rack 41 formed on a rod 48 extending rearwardly from the tracer slide 23. Thus the reciprocatory movements of the spindle l3 are communicated to the tracer slide through the shafts 29 and 32 and the gears 40 and 4| or 40 and 42. The movements of the spindle I3 and slide 23 are in the same direction when the gear 40 is meshed with the gear 42 and in opposite directions when the gear 40 is meshed with the gear 4! The gears 4| and 42 are shiftable preferably by means of a. lever 49 (see Figure 2) pivoted on a bracket 50 formed on the gear box 39. One end of the lever 49 is formed with two legs to straddle the hub of the gear 4|, each leg having a pin 5| engaging in an annular groove 52 formed in the hub of the gear. Thus the gears 4i and 42 may be shifted axially of the shaft 43 to cause one or the other to mesh with the driving gear 40 by rocking the lever 49 about its pivot. A spring 53 secured to a rearward extension of the lever is normally operative to hold the gears 4 and 4 in mesh. A solenoid 54 having its armature 54-A suitably secured to the other end of the lever 49 operates when energized to shift the gear assembly and mesh the gear. 42 with the driving gear 40 for reverse operation of the machine. This reversing operation may also be effected manually when desired through the medium of a handle 55 constituting an extension of'the lever 49.

Referring to Figures 4; and 5, the micrometer adjusting mechanism 36 comprises a worm wheel 59 keyed to the lower end of the shaft 32 and rigidly held in place thereon by a set screw 59-A disposed opposite the keyway. The worm wheel is enclosed in an annular housing 60 formed integral or rigidly secured to'the sleeve 35. Meshing with the worm wheel 59 is a worm 6| fast on a transverse shaft 62 journaled \in bearings 63 mounted on the housing 60. In the present instance the bearings 63 are threaded into the housing so that they may be conveniently adjusted to remove all end play with the shaft 62.

The shaft 62 is providedat opposite ends with hand wheels 64 by which it may be rotated and, through the action of the worm BI and worm wheel 59, thus rotate the sleeve 35 relative to the shaft 32. Since the sleeve 35 is drivingly connected with the shaft 28 through the clutch'teeth 34, it

- will be apparent that this operation serves to rotate the shaft 32 relative to the shaft 28. This movement is communicated to the tracer slide in the usual way so that the relative position of the tracer tip 2'! and the tool i4 may be varied accurately in infinitely small steps to accurately 'position them in desired relationship to the pattern and the Work. Accurate adjustment is facilitated by the provision of a graduatedscale 85 on the hub of each of the hand wheels 64.

The micrometer adjustment above described may be utilized to advantage in initially setting up the machine as it makes it unnecessary to 'place the pattern in exactly the same plane as the work piece. After the work and pattern are mounted'on the support I, the tool I4 may be advanced into contact with the work independently of the tracer by disengaging the clutch 34.

The clutch is then engaged and the tracer tip advanced. into contact with the pattern by manipulating the hand wheel 64. When the tracer is to be moved through a considerable distance, this may be done conveniently and rapidly by disengaging the clutch 34 and rotating the entire micrometer mechanism.

The clutch 34 is then engaged and the tracer tip is backed away from the pattern by operating the hand wheel 64. The extent of this backward movement determines the depth of the cut taken by the tool I4 in the surface of the work piece.

For precision work it is essential for'the tracer to follow the movement of the tool exactly, as any lost motion between these partswill necessarily result in inaccurate reproduction. Means are provided in the present instance for eliminating all possibility of such lost motion by effectually taking up the play and backlash in the ported on a bracket ll.

gears, clutch and other parts of the spindle and slide connecting mechanism.

To this end the rod 48 by which the tracer slide 23 is driven; is provided at its rear 'end with a piston 66 operating in a closed cylinder 61 sup- Provision is made for supplying pressure fluid to the rear end of the cylinder through a duct 68 (see Figure 1) so that when the machine isin operation, the piston is continuously yieldably urged in a direction tending to move the slide 23 and tracer toward the pattern. With this arrangement all backlash in the gears and clutch mechanism is taken up and the tracer and tool spindle are moved together in exactly the same degree either in the same or in opposite directions.

Referring now more particularly to Figures 6 and '7, the tracer 24 which constitutes the essential portion of the present invention, and

. which controls the forward and backward movements ofthe tool spindle and tracer slide, comprises an elongated hollow casing constructed in the present instance in three sections II, 12 and I3 rigidly secured together to form. a unitary tracer head structure.

The section II disposed at the rear end of the assembly constitutes a housing for the tracer valve and to this end is provided with a series of three ports I4, 15 and 16 arranged in a line extending longitudinally of the casing. A fourth port 11 is located at one side of the port 15 as will be seen by reference to Figure 2 of the drawings.

Connecting with the port TI is a duct I8 (see particularly Figures 1 and 7) leading from the discharge or pressure side of the source of supply Ducts l9 and 88 extend from the ports 14 and 16, respectively, to a reversing valve .(not shown) which valve in turn is connected with opposite ends of the spindle actuating cylinder I6 (not shown). A discharge duct or drain83 extends from the port 11 (see Figure 1) to the sump of the pump.

The casing section II is closed at one end by the section 12 and at the other end by an end plate 84, the several parts being rigidly secured together by bolts 85. As herein shown, the end plate 84 is provided with a depending arm 86 constituting a bracket for supporting the casing structure on the slide 23.

Enclosed within the casing II is a cylindricalsleeve 81 formed with accurately spaced internal circumferential grooves 88, 89 and 98 communicating with the ports I4, 15 and I6 through apertures 88--A, 89-A and 98-A extending through the sleeve. As herein shown, the sleeve 81 is constructed in three parts to facilitate manufacturing within the extremely close limits essential for this type of mechanism. The sleeve is fitted tightly in-the casing section II and held rigidly in place against an internal shoulder 9| on the casing wall by an annular member 92 carried on the end of the casing section I2 and disposed so as to abut against the end of the sleeve. With this construction, accurately dimensioned openings for the ports 14, I5 and 16 are readily obtained with ordinary manufacturing processes.

Communication between the several ports in the casing is controlled by a hollow, cylindrical valve member 93 slidably mounted for endwise movement in the sleeve 81. The valve member is formed with .accurately spaced peripheral grooves 94, 95 and 96 adapted to co-operate with the grooves 88, 89 and 98 in defining passages between the ports. The outermost or end grooves 94 and 96 are provided with apertures 91 communicating with the interior of the member groove 95 connects the ports 15, and 14 so as to direct pressure fluid from the duct I8 into the duct 19. At the same time, the port 16 is connected to the port 11 by way of the groove 96 and aperture 91. Movement of the valve member 93 in the other direction from neutral position connects the port 15 with the port 16 and likewise connects the port 14 with the port 11. Thus, by small movements of the valve member, the ducts l9 and 88 leading to the spindle actuating cylinder I6 may be connected selectively with the pressure duct I8 orthe drainduct 83.

Suitable means is provided for confining the movement of the valve member 93 within predetermined limits. As herein shown this means comprises an annular member I8I secured to the end of the sleeve 81 adjacent the retaining member 92 by means of screws I82, the retaining member being slotted as at I83 to accommodate the heads of the screws. The member IN is formed with an accurately dimensioned internal peripheral notch I84 adapted to receive an annular member I85 rigidly secured to the valve member 93. The depth of the slot I84 is greater than the thickness of the member I85, the difference representing the range of movement of the member in the slot and therefore the range of movement of the valve member.

When the machine is in operation movements of the valve member 93 are controlled by the tracer arm 25 through the medium of a valve actuating member I06 slidably mounted for endwise movement in the casing section 12. In the embodiment shown in Figure 7 of the drawings.-

a push rod I01 slidably supported in a gland I mounted in the end of the casing section 12 provides an operative connection between the valve .member and the actuating member.

The push rod bears against a pad I00 on a transverse web I09-A rigid with ,the valve member, the pad being disposed substantially centrally of and co-axially in the member. A compression spring IIO interposed between the pad I09 and a collar III anchored to the push rod tends to urge the rod and valve member apart for reasons that will appear presently.

Bearing against the opposite side of the pad I09 is a second push rod II2 slidably supported in a gland I I3 mounted in the end plate 04. The rod II2 extends rearwardly through a tubular extension II4 of the end plate 84 and through a hollow adjusting screw I I5 threaded into the same. A compression spring II6 interposed between the end of the screw H5 and a collar II1 abutting against a shoulder on the push rod, urges the rod to the left as viewed in Figure 7 and thus tends to shift the valve member to the left against the action of the spring H0. The

spring H6 is of heavier construction than the spring IIO so that the pad I09 is normally held in tight engagement with the push rod I01 and the latter is urged to the left against the actuating member I 06. The pressure exerted by the spring II 6 may be readily adjusted by turning the screw II5.

The impositive connection ,between the valve member 93 and the operating elements provided by the construction above described makes it unnecessary to aline the push rod bearings exactly with the bore of the valve member, thus materially simplifying the manufacture and assembly of the parts. The valve member, is enabled to move freely without binding andconsequently responds more quickly and accurately to slight movements of the actuating member I06 'under the influence of the tracer arm 25. The

valve actuating member I06 is preferably of hollow cylindrical construction and is provided at each end with a peripheral bearing surface III! for sliding engagement with the walls of a cylindrical hardened steel bearing member H0 mounted in the casing section 12.

As shown in Figure 6 the tracer arm 25 is operatively connected to the abutting member I06 by means of a ball and socket joint comprising a ball member I20 rigidly mounted on the inner end of the tracer arm 25, and a socket I2I supported within and substantially centrally of the actuating member so that the assembled parts occupy a. minimum of space and yet provide a relatively long and firm bearing for the same. An annular retaining ring I22 threaded into the open end of the socket andlocked in place by a suitable lock nut I23 maintains the ball I20 securely in the socket. The tracer arm extends entirely through the tubular casing 13 which is threaded into the end of the section '12 and locked in place by a suitable lock nut I24 to provide a convenient means for adjusting the overall I length of the casing structure. Mounted intermediate the ends of the tracer arm adjacent the forward end of the section 13 is a bearing element I25 having a spherically formed hearing surface I 26 adapted to co-act with an inclined bearing surface I21 formed within a hollow cylindrical stationary bearing element I20 threaded into the end of the casing section 13. The interior diameter of the element I26 is sufficiently greater than the diameter of the tracer arm and the element I25 so that the arm may be rocked about the pivot provided by the ball and socket joint when pressure is exerted laterally on the tracer tip 21.. A nut I29 threaded on the bearing element prevents accidental movement of the element relative to the casing.

As shown in Figure 8 the relative positioning of the bearing surfaces I26 and I21 is such that when the tracer arm 25 is rocked about its pivot,

.the bearing surface I26 rides upon the inclined surface I21 and shifts the tracer arm axially a distance determined by the degree of deflection of the arm 25. The bearing I25 is normally centered in the bearing I28 by a compression spring I30 enclosed in a cap or guard I3I threaded on the tracer arm and bearing against the end of the element I28. The pressure exerted by the spring on the tracer arm may be varied by rotating the cap I3I and determines the force required to rock the tracer arm out of normal or intermediate position.

It will thus be appreciated that the tracer arm 25 may be moved axially as well as laterally by reason of the tip 21 encountering a rise in the surface of the pattern. In either case, the valve actuating member I06 is moved endwise a proportionate amount and acts through the push rod I01 to, position the valve member 93. The relative positioning of the several parts is extremely important and these are preferably adjusted so that the valve member 93 may be shifted to its extreme forward operative position by the spring H6 and push rod II2 when the bearing I26 is exactly centered in the bearing I21 and in engagement therewith. A slight rearward movement of the tracer arm produced by either axial or lateral pressure of the pattern against the tip 21 serves to shift the valve member to neutral position. Further movement of the tracer arm shifts the valve member to its other operative position in which the hydraulic circuit connections are reversed. Adjustment of the several parts is quickly and accurately effected by rotation of the casing section 13 relative to the section 12 and by rotation of the'bearing element I28 relative to the casing section 13.

When the machine is in operation, the tip 21 is held in constant, substantially uniform contact with the surface of the pattern 9. The contact pressure is determined by the adjustment of the springs H6 and I30. When the tip enters a depression in the pattern, the valve member 03 follows under the influence of the spring H6 and positions the valve ports so as to produce an appropriate movement of the tool I4. When the tip 21 encounters a rise in the surface of the pattern the tracer arm is shifted rearwardly to vary the position of the valve member in the reverse direction.

The tool and tracer may be backed away from the work and pattern under manual control when they are to be shifted to new traversing paths. To this end means are provided for moving the valve member 93 to its rearward position independently. of the tracer arm. In the embodiment shown in Figure 7, this means comprises a solenoid I32 supported by a bracket I33 mounted on the end plate 86 of the casing and having its armature I34 operatively connected with the projecting end of the push rod II2. When energized, the solenoid I32 draws the push rod out of engagement Withthe pad I09 on the valve member, whereby the spring H0 is rendered effective to shift the valve member to the right.

Upon de-energization of the solenoid, the push rod H2 is shifted back into engagement with the pad I09 by the spring I I6 and the valve member is returned to the position determined by the position of the tracer arm.

Figure 10 shows a modified valve control mechanism wherein the push rod is moved out of engage'ment with the valve member by manually operable means. In this construction, a nut I35 is threaded on the projecting end of the push rod H2 and is locked'by a second nut I36. The

nut I35 constitutes a thrust bearing for engagementwith the free end of a crank arm I31 carried by a shaft I38 rotatably supported on a bracket I39 on the end plate 84. A cam I40 fast on a shaft I4I also journaled in the bracket I39'is arranged to engage the crank arm 'I3I intermediate its ends. The cam is so shaped that when the shaft MI is rotated, the crank arm I31 is rocked between a forward position in which the push rod is disengaged from the arm, to a rearward position in which the push rod is shifted to the right sufliciently to permit the valve member 93 to move to its rearmost position under the influence of the spring H0,

For rotation of the shaft I M a vertical shaft journaled at its upper end in a bearing I43 mounted on the bracket I39 carries a bevel gear MII' meshing with a bevel gear I45 fast on the shaft I lI. Any suitable means such as a manually operated lever (not shown) may be utilized to rotate the shaft M2. As hereinshown.

a spring Mlianchored at one end to a pin I41 projecting transverse from the shaft MI and at the other end to a pin I48 threaded into the end plate 84 acts to normally maintain the low point of the cam I40 in engagement with the arm I01. Thus, the push rod H2 is normally free to move through its full stroke without interference. When the shaft MI is rotated through a quarter turn, the cam I40 operates through the arm I31 to shift the push rod and valve member 93 to neutral position. A further quarter turn of the shaft I4I shifts the valve member to its extreme rearward position. A furthe odification of the tracer valve actuating m chanism is shown in Figure 10. In

' end play between the rod and the valve member and yet permit lateral shifting of theparts so that the push rod may readily center itself with respect to the valve member without causing the member to bind in the sleeve 81.

The push rod I01 is also modified in this instance by the provision of an enlarged hollow end portion I53 adapted to fit over the nut I52, thereby permitting the push rod to bear directly against the pad I09. No compression spring corresponding to the'spring I I0 is required in this construction.

Any suitable means may be supplied for withdrawing the push rod II2 to its rearward position .to shift the valve member 93. As herein shown, a solenoid I54 is provided for this purpose. The solenoid is mounted on a bracket I55 supported on the end plate 84 of the casing structure and its armature I56 is connected by a link member reaches its limit position. Further movement of the lever shifts the sleeve I60 axially of the push rod against the action of the spring -I6I.

With this construction, the solenoid armature I 56 is'enabledto make a full stroke without necessitating accurate adjustment of such strokewith reference to the stroke of the valve member. A

coiled spring I63 connection between the lever I58 and ,the bracket I55 withdraws the lever from engagement with the sleeve I60 upon deenergization of the solenoid and the push rod is returned to normal position by the spring H6.

The tracer solenoid I32 may be controlled in any suitable ma ner preferably from a switch or push button lgiarranged in a convenient position for the ope tor and this push button controls the circuit, the latter being supplied with current from any suitable source. Theparts of the machine (which do not constitute a portion operation and thus cause the tool to be fed towards the work.-

To control the tracer by the solenoid I32 all that is necessary for the operator to do is to actuate the push button or switch I60.

While the preferred forms of the invention have been herein shown and described, it .is to be understood that various changes may be made in the details of-construction and in the combination and arrangement of the several parts, within the scope of the claims, without departing from the spirit of this invention.

What is claimed as new is:

'1. In a. tracerv mechanism, incombination, an elongated-hollow casing structure, a valve actuating member supported in one end of the casing for endwise movements relative to the casing, a tracer arm pivotally connected to said member and projecting through the other end of the casing, said arm having a tip adapted to engage the surface of a pattern, a bearing element having a spherically formed bearing surface carried by saidann adjacent said other end of the casing and adapted to cooperate with a secondbearing element supported on the casing, said second bearing element having a bearing surface disposed at an angle to the axis of the casing where-- by lateral deflections of the tracer, arm and tip are operative to produce an axial movement of I of the present invention but which are described the arm and endwise movement of said valve ac- I tuating member, and yielding means tending normally to center said bearing elements one with respect to the other. v

2. In a tracer mechanism, in combination, an

ating member supported in one end of the casing for endwise movements relative to the casing, a tracer arm pivotally connected to said member and projecting through the other end of the casing, said arm having a tip adapted to engage the surface of a pattern, and means supporting said tracer arm intermediate its ends whereby lateral movements of the arm about its pivot are effective to impart endwise movement to said valve actuating member, said supporting means comprising a bearing element having a spherically formed surface fast on said arm, a second bearing element supported on the casing and having an inclined bearing surface on which said spherical bearing surface is adapted to slide in the lateral movement of said arm, and resilient means tending normally to center the first saidbearing element with respect to the second said bearing element.

3. In a tracer mechanism, in combination, an elongated hollow casing structure, a valve actuating member supported in one end of the casing for endwise movements relative to the casing, a tracer 'arm pivotally connected to said member and projecting through the other end of the casing, said arm having a tip adapted to engage the surface of a pattern, and means supporting said tracer arm intermediate its ends whereby lateral movements of the arm about its pivot are effective to impart endwise movement to said valve actuating member, said supporting means comprising co-operating bearing elements on said arm and said casing, said elements having slidably engaging bearing surfaces disposed relative to each other so that lateral movement of one element relative to the other 'element is effective to impart an axial movement to said am, resilient means tending normally to center said bearingelements, one with respect to the other,

and means whereby the stress of said resilient means may be varied at will. 7

'4. In a tracer mechanism, in combination, a casing structure, a tracer arm supported by said casing structure for universal movement, a valve actuating member adapted to be shifted axially of the casing in response to movements of said arm, a valve for controlling the flow of pressure fluid between inlet and outletfports in said casing, said valve including a cylindrical valve member supported for movement axially of the casing, means yieldably urging said valve member toward one end of the casing, and means operatively connecting said valve member with said actuating-member for movement thereby against the action of said yieldable means, said connecting means comprising a rod supported for endwise sliding movement in the casing and bearing at 011-- posite ends against said actuating member and said valve member.

5. In a tracer mechanism, in combination, a casing structure, a tracer arm supported by said casing. structure for universal movement, a valve actuating member adapted to be shifted axially of the casing in response to movements of said arm, a valve for controlling the flow of pressure fluid between inlet and outletports in said casing, said valve including a cylindrical valve member supported for movement axially oi the casing, and having a pad rigidly supported co-axially therein, a rod slidably supported adjacent one end of the member with one end disposed so as to engage one side of said pad, spring means acting on said rod tending to shift said valve member toward one end of the casing, a second rod elongated hollow casing structure, a valve actuslidably supported adjacent the other end of the member with one end engaging the other side of said pad and the other end engaging said valve actuating member to provide an operative connection between the valve member and the actuating member, and spring means interposed between said second rod and said pad operative to shift said valve member toward the other end of the casing when said first lJd is drawn out of engagement with said pad.

6. In a tracer mechanism, in combination, a casing structure, a tracer arm supported by said casing structure for universal movement, a valve actuating member adapted to be shifted axially of the casing in response to movements of said arm, a valve for controlling the flow of pressure fluid between inlet and outlet ports in said casing, said valve including a cylindrical valve member supported for movement axially of the casing, means operatively connecting said actuating member and said valve member including means yieldably urging the valve member toward one end of the casing, a rod slidably supported at one end of the casing having one end positioned for engagement with said valve member, spring means acting on said rod to yieldably urge said valve member toward the other end of the casing against the action of said connecting means, and means including a solenoid for withdrawing said rod from engagement with said valve member to render the connecting means operative to move the valve member toward said one end of the casing.

7. In a tracer mechanism, in combination, a valve having a member movable from a neutral position to either of two operative positions, a tracer arm adapted to control the position of said member, and means for moving said member into one operative position independently of said tracer arm.

8. In a tracer mechanism, in combination, a valve having a member movable from a neutral position to either of two operative positions, a tracer arm adapted to control the position of said member, a solenoid adapted when energized to move said member into one operative position independently of said tracer arm, and circuit connections controlled from a remote point for energizing said solenoid.

9. In a tracer mechanism, in combination, a valve having a member movable from a neutral position to-either of two operative positions, a tracer arm adapted to control the position of said member, and manually operable means for moving said valve member into one operative position independently of said tracer arm.

10. In a tracer mechanism, in combination, a casing structure, a tracer arm supported by said casing structure for universal movement, a valve actuating member adapted to be shifted axially of the casing in response to movements of said arm, a valve for controlling the flow of pressure fluid between inlet and outlet ports-in said casing, said valve including a cylindrical valve member supported for movement axially of the easing, means operatively connecting said actuating member and said valve member including means yieldably urging the valve member toward one end of the casing, a rod slidably supported'at one 7 end of the casing having one end positioned for engagement with said valve member, spring means acting on said rod to yieldably urge said valve member toward the other end of the casing against the action of said connecting means, a crank arm operable to withdraw said rod from engagement with said valve member to render the connecting means operative to move the valve member toward one end of the casing, and a cam for actuating said crank arm.

- 11. In a tracer mechanism, in combination, a valve having a member movable from a neutral position to either of two operative positions, a

tracer arm adapted to control the position of said member, and manually operable means for mov.-

embodying a crank arm, a cam operable upon said 5 crank arm, and means for actuating the cam.

EINAR K. JOHANSEN. 

